[Elecraft] KX1 BFO Calibration

Tue Dec 30 21:02:00 2003

Don, you are correct.  CHU transmits USB with a re-introduced carrier. 
This morning I tried tuning USB until the carrier (a continuous tone) 
was at zero on Spectrogram.  I then switched to LSB and did the same 
thing.  The difference divided by two was -0.30, much more in line with 
what Wayne said was typical.  Now both USB and LSB are close.  Still a 
bit of a problem in that 1) the carrier in USB is at zero, but in LSB it 
is about 400 Hz, and 2) the 1000 Hz tone is not 1000 Hz above the 
carrier.  Closer to 940 to 950 Hz.  I'm off to work, but will post more 
later.

Randy, K7TQ

Don Wilhelm wrote:

> Randy,
> 
> You might want to check the CHU transmission.  My fuzzy memory understanding
> is that they transmit single sideband with carrier.  IF that is true, AND
> you set things up on their 1000 Hz ticks, you could end up being either 1
> kHz or 2 kHz off depending on exactly how you did the alignment.
> 
> 73,
> Don W3FPR
> 
> ----- Original Message -----
> From: "Randy Foltz" <[email protected]>
> To: <[email protected]>
> Sent: Tuesday, December 30, 2003 1:45 AM
> Subject: [Elecraft] KX1 BFO Calibration
> 
> 
> 
>>After making several 40 m QSOs, I decided to do the BFO calibration.
>>After a 15 minute warm up period I tuned CHU at 7.335 MHz.  The BFO
>>parameter was set to .00 and the DDS one to 00.  Using Spectrogram to
>>display the 1000 Hz tick marks I recorded the fq as 7334.74 in USB and
>>7337.35 in LSB.  This difference is 2.61 and when divided by 2 gives a
>>BFO correction of 1.30. Since the USB was lower the correction should be
>>-1.30.  Woops, the maximum negative value is 0.99.
>>
>>I went ahead and set the -0.99 and recorded the fqs again.  This time
>>they were 7335.74 for USB and 7336.36 for LSB.  Closer together, but
>>still not the same.
>>
>>I took out the ATU, repeated the test, and the results were the same.
>>
>>Any suggestions?
>>
>>Randy, K7TQ
>>
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> 
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